A Developed and Validated High-Performance Thin-Layer Chromatographic Method for the Quantitative Determination of Quercetin in Satyrium nepalense Tubers

Satyrium nepalense D. Don (Orchidaceae) is a reservoir of numerous chemical compounds such as flavonoids, glycosides, and unsaturated sterols/triterpenes. Thin-layer chromatography (TLC) and qualitative tests confirm the presence of quercetin in S. nepalense tubers — this is why we must pay attention to its chemistry. A simple, sensitive, and accurate method developed with a normal-phase high-performance thin-layer chromatography (HPTLC) has been optimised for the separation, identification, and quantitative estimation of quercetin in the methanol extract of S. nepalense tubers. Chromatography was performed by using aluminum TLC plates precoated with silica gel 60 F254 using toluene—ethyl acetate—formic acid (7:5:1, v/v) as the solvent system at 25 ± 2°C. Linear ascending development was carried out in a saturated twin-trough glass chamber. Densitometric determinations were performed in reflectance—absorbance mode by using a deuterium lamp (D2) for excitation at 366 nm and a K400 filter in order to measure the emitted light by using a CAMAG TLC Scanner 3. S. nepalense (tuber) contained 40.28 mg/100 g extract DW of quercetin. The detector response was linear for concentrations with a range of 2–12 µg band−1 through a correlation coefficient (r) of 0.97874 with respect to peak area. The method has a significant precision (0.71%) and repeatability (0.74%), as far as the percentage value; the standard deviation was found to be less than 2. The accuracy of this method was checked by doing some recovery experiment at three different levels, by using the standard addition method; in fact, values were discovered to be 99.50–100.24%. There are no reports concerning the quantitative assessment of quercetin in the S. nepalense. Hence, an efficient HPTLC method has been developed and validated. It is simple, fast, reliable, specific, precise, and useful for routine assays of S. nepalense extracts containing quercetin.